NASA: A technique called photodynamic therapy, originally developed for commercial plant growth research on the Space Shuttle, has been used by surgeons in two successful operations for brain tumors. The device uses pin-head-size light emitting diodes (LEDs) that release long, cool, wavelengths of light which activate photosensitive antineoplastic drugs. The device is being adapted to non-space uses through a Small Business Innovation Research grant. The LEDs also are used to treat skin cancer, psoriasis, and rheumatoid arthritis. Research is being conducted regarding LED use in wound healing, tissue growth, and prevention of muscle and bone atrophy in astronauts.